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Title: Apparatus for releasing a pipe string from an object struck downhole by continuously applying tension to the apparatus

Patent ·
OSTI ID:6878228

This patent describes apparatus adapted to be connected between a pipe string and an object stuck in a wellbore for disconnecting the pipe string from the object. It comprises: disconnection means responsive to a continuously applied pulling force of predetermined magnitude applied to the pipe string for a predetermined period of time for disconnecting the pipe string from the object stuck in the wellbore, including an inner member adapted to be connected to the object, an outer member connected to the inner member and adapted to be connected to the pipe string, and compressible means disposed between the inner and outer members. This patent also describes a method of releasing a pipe string from an object stuck downhole in a wellbore. It comprises: releasing a connection between the pipe string and the object stuck downhole in response to a continuously applied pulling force of predetermined magnitude applied to the pipe string for a predetermined period of time. It comprises: compressing an permanently deforming a crushable element in response to the pulling force applied to the pipe string, the crushable element being permanently deformed when the predetermined period of time has elapsed, and disconnecting the pipe string from the object when the crushable element is deformed.

Assignee:
Schlumberger Technology Corp., Houston, TX (United States)
Patent Number(s):
US 5158142; A
Application Number:
PPN: US 7-722041
OSTI ID:
6878228
Resource Relation:
Patent File Date: 27 Jun 1991
Country of Publication:
United States
Language:
English